1. Field of the Invention
The present invention relates to a steering control apparatus and a steering control method, and more particularly, to a technology of removing a disturbance generated inside or outside a vehicle.
2. Description of the Prior Art
An electric power steering apparatus of a vehicle includes a torque sensor configured to sense the torque of a steering shaft connected to a steering wheel, an electric motor linked with a steering output shaft or a rack bar to rotate/move the steering output shaft or the rack bar, a steering ECU configured to control the rotation of the electric motor according to a steering torque value measured by the torque sensor, and so on.
The electric power steering apparatus basically performs an operation of generating a steering assist current to be proportional to the steering torque according to a driver's operation of the steering wheel so as to rotate the electric motor. That is, the electric power steering apparatus performs a basic operation for assisting the user's steering force.
In such a steering control apparatus, an undesired disturbance component may be included between an input value and an output value due to various factors on both the inside and outside of a vehicle.
The term “disturbance” may be interpreted, in general technical meaning, as causing a change in a control amount in an automatic control despite not being a standard input, and such a disturbance may also occur in the steering control apparatus due to various causes.
The steering control apparatus should compensate for a steering control value in order to offset such a disturbance, but a compensation method may vary according to the cause of the disturbance.
Accordingly, it is necessary to pay compensation for properly removing the disturbance of the steering control apparatus in which various causes compositely operate. Disturbance offsetting techniques, which have been proposed up to now, have handled an individual cause, but technologies for offsetting the disturbance of the steering control apparatus, which occurs due to composite causes, have not been sufficiently developed.